Method for selecting the composition of a construction material comprising an excavated clay soil, method and system for preparing such a construction material

Abstract

The invention relates to a method (100) for selecting the composition of a construction material including an excavated clay soil, said construction material composition to include deflocculating agent and activating agent quantities adapted to the excavated clay soil, said method including a step of receiving (130) a measured value of at least one physicochemical property of an excavated clay soil, and a step of selecting (170) a deflocculating agent quantity and an activating agent quantity adapted to the excavated clay soil. In addition, the invention also relates to a method (200) for calibrating a calculation algorithm for determining the composition of a site construction material, to a construction material formed from an excavated clay soil, and to a system (400) for preparing a construction material including an excavated clay soil.

The invention claimed is: 
     
       1. A method for selecting the composition of a construction material including an excavated clay soil, said construction material composition to include deflocculating agent and activating agent quantities adapted to the excavated clay soil, said method being implemented by a computer device including a calculation module, said method including:
 A step of receiving, from the calculation module, a measured value of at least one physicochemical property of an excavated clay soil; and 
 A step of selecting, by the calculation module, a deflocculating agent quantity and an activating agent quantity adapted to the excavated clay soil based on a comparison of the measured value with reference values, said reference values including correlations between prior-measured values of the at least one physicochemical property of a clay soil and deflocculating agent and activating agent quantities adapted to said clay soil to form a construction material. 
 
     
     
       2. The method according to  claim 1 , wherein the at least one physicochemical property is selected from: content of clays in the excavated clay soil, nature of the clays, particle size, content of impurities, content of non-clay mineralogical fractions, content of contaminants, elemental analysis, content of metal oxides, salinity, pH, and total exchange capacity of clays in the excavated clay soil. 
     
     
       3. The method according to  claim 1 , wherein the at least one physicochemical property is measured on a pretreated excavated clay soil, said pretreatment being selected from: crushing, sorting, sieving, and/or drying of the excavated clay soil. 
     
     
       4. The method according to  claim 1 , first comprising receiving a selected mechanical property value of the construction material, the step of selecting the deflocculating agent and activating agent quantities further including excluding the deflocculating agent and activating agent quantities which will not allow the construction material to exhibit the selected mechanical property value. 
     
     
       5. The method according to  claim 1 , wherein the step of selecting, by the calculation module, a deflocculating agent quantity and of activating agent quantity adapted to the excavated clay soil includes implementing a previously calibrated calculation algorithm. 
     
     
       6. The method according to  claim 5 , wherein the previously calibrated calculation algorithm has been obtained by implementing a statistical supervised learning method. 
     
     
       7. A method for preparing a construction material from an excavated clay soil, the method including:
 A step of measuring at least one physicochemical property of the excavated clay soil; 
 A step of selecting the composition of a construction material including an excavated clay soil according to the method of  claim 1 ; and 
 A step of mixing the excavated clay soil, a deflocculating agent, and an activating agent according to the selected composition. 
 
     
     
       8. The preparation method according to  claim 7  further including:
 a step of measuring physicochemical or mechanical properties of the construction material being formed, during the mixing step, 
 a step of comparing the measured values with predetermined values of physicochemical or mechanical properties of the construction material being formed, and 
 when the measured values differ from the predetermined values of physicochemical or mechanical properties of the construction material being formed, a step of adding at least one complementary ingredient. 
 
     
     
       9. A construction material formed from an excavated clay soil, comprising an excavated clay soil, an activating agent, and a deflocculating agent, said deflocculating agent accounting for at least 0.1 wt % of the construction material, said activating agent being an alkaline activating composition. 
     
     
       10. The construction material according to  claim 9 , further comprising a mixture of different types of clays. 
     
     
       11. The construction material according to  claim 9 , further comprising metal oxides at a content of at least 2 wt % of the construction material. 
     
     
       12. The construction material according to  claim 9 , further comprising blast furnace slag. 
     
     
       13. The construction material according to  claim 12 , comprising:
 30% to 80 wt % of an excavated clay soil, 
 0.1% to 10 wt % of a deflocculating agent, and 
 5 to 10 wt % of blast furnace slag. 
 
     
     
       14. The construction material according to  claim 12 , comprising:
 between 5 and 20 wt % of raw clay from the excavated clay soil; 
 between 0.1 and 3 wt % of a deflocculating agent; 
 between 3 and 15 wt % of an activating agent; 
 between 25 and 45 wt % of sand; and 
 between 35 and 55 wt % of aggregates. 
 
     
     
       15. The construction material according to  claim 9 , further comprising at least 2 wt % of silt particles. 
     
     
       16. The construction material according to  claim 9 , wherein the excavated clay soil has been pretreated, said pretreatment being selected from: crushing, sorting, sieving, and/or drying of the excavated clay soil. 
     
     
       17. A method for preparing the construction material according to  claim 9  from an excavated clay soil including:
 a step of excavating a clay soil including stones 2 cm in size or greater; 
 a step of screening the excavated clay soil to remove said stones 2 cm in size or greater; 
 a step of mixing the excavated clay soil, a deflocculating agent, and an activating agent. 
 
     
     
       18. The construction material according to  claim 11 , said construction material corresponding to a construction binder. 
     
     
       19. The construction material according to  claim 13 , said construction material corresponding to a construction binder. 
     
     
       20. The construction material according to  claim 14 , said construction material corresponding to a site concrete. 
     
     
       21. The construction material according to  claim 9 , said alkaline activating composition including a compound having a pKa greater than or equal to 10. 
     
     
       22. A construction material formed from an excavated clay soil, comprising an excavated clay soil, an activating agent, and a deflocculating agent, said deflocculating agent accounting for at least 0.25 wt % of the construction material. 
     
     
       23. A method for calibrating a calculation algorithm for determining the composition of a construction material implemented by a digital device including a learning module, said method comprising:
 A first step of receiving, from the learning module, a measured value of at least one physicochemical property of an excavated clay soil; 
 A second step of receiving, from the learning module, a deflocculating agent quantity value and an activating agent quantity value which, once added to the excavated clay soil, allow a construction material to be formed; 
 A third step of receiving, from the learning module, a measured value of at least one mechanical property of the construction material formed from the excavated clay soil, the measured value of at least one physicochemical property that was received during the first step, and the deflocculating agent and activating agent quantities received during the second step; and 
 A step of creating a correlation, by the learning module, between the measured values received so as to calibrate a calculation algorithm. 
 
     
     
       24. A system for preparing a construction material including an excavated clay soil, said system comprising:
 At least one container including an excavated clay soil, 
 At least one container including a deflocculating agent, 
 At least one container including an activating agent, 
 A mixing device, with automated transport means between the containers and the mixing device, 
 A control module configured to generate output signals for use by the automated transport means so as to transport determined quantities of the deflocculating agent and the activating agent to the mixing device. 
 
     
     
       25. The system for preparing a construction material according to  claim 24 , further comprising a communication means configured to receive data on a determined deflocculating agent quantity and a determined activating agent quantity, adapted to the excavated clay soil; the control module being configured to generate output signals for use by the automated transport means so as to transport the determined deflocculating agent and activating agent quantities to the mixing device. 
     
     
       26. The system for preparing a construction material according to  claim 24 , further comprising:
 A means for measuring at least one physicochemical property of the excavated clay soil, 
 A calculation means adapted to implement a computer program configured to perform:
 A step of obtaining a measured value of at least one physicochemical property of the excavated clay soil; and 
 A step of determining a deflocculating agent quantity and an activating agent quantity suitable for the excavated clay soil based on a comparison of the one or more measured values with reference values.